The present invention relates to a mirror device, an optical switch, an electronic instrument, and a mirror device driving method.
One problem when driving a mirror device is how to produce a large displacement for a mirror with a smaller driving force.
In order to solve this problem, Japanese Patent Application Laid-Open No. 2001-311900 proposes an optical scanning apparatus that is equipped with opposing electrodes that have inclined surfaces on their lower surfaces in a mirror driving direction, with grooves being provided in the incline direction of these inclined surfaces.
When the driving force for driving the mirror device is provided electrostatically by a coulomb force, for example, the driving force is dependent on distance in that the driving force increases as the distance between the electrodes decreases and decreases as the distance between the electrodes increases.
Accordingly, although it is believed that the technology of Japanese Patent Application Laid-Open No. 2001-311900 can be applied when the slopes are gradual, the distance between the mirror and the counter electrodes increases as the slope angles increase, so that a larger driving force becomes necessary. In this way, it is not possible to suitably solve the problem of producing a larger driving effect to a mirror with a smaller driving force.
In view of the above problem, the present invention is intended to provide a mirror device, an optical switch, an electronic instrument, and a mirror device driving method that can produce a larger driving effect to a mirror with a smaller driving force.